Photosynthetic Photon Flux Density (PPFD)

Photosynthetic Photon Flux Density (PPFD) is the PPF incident upon a square meter with units of or µmol/m2s. In other words, the PPFD is a given PPF over a specific area, such as a canopy. It is a measure of intensity of light in a given area, not a measurement of overall light output.